Does any1 know what it would take to improve Foveon high ISO performance?

The Foveon really does seem to be an amazing sensor. Of course the million dollar question about this sensor is, how will Sigma be able to improve the higher ISO performance of it? What will they/can they do to improve this? Is this a simple computing issue, down to needing massive processing power? Or is it related and possibly limited to the three layer nature of the sensor- which unfortunately by design simply cannot capture light as well as single layer sensors? I must admit for all the amazing qualities of this sensor it would be a major bummer if the sensor could never be developed to take the kind of higher ISO pics that now so many cams allow? Thoughts? thanks, jeremy